A Rechargeable Urea‐Assisted Zn‐Air Battery With High Energy Efficiency and Fast‐Charging Enabled by Engineering High‐Energy Interfacial Structures.

Electrochemical urea oxidation reaction (UOR) offers a promising alternative to the oxygen evolution reaction (OER) in clean energy conversion and storage systems. Nickel‐based catalysts are regarded as highly promising electrocatalysts for the UOR. However, their effectiveness is significantly hindered by the unavoidable self‐oxidation reaction of nickel species during UOR. To address this challenge, we proposed an interface chemistry modulation strategy to boost UOR kinetics by creating a high‐energy interfacial heterostructure. This heterostructure incorporates Ag at the CoOOH@NiOOH heterojunction interface, where strong interactions significantly promote the electron exchanges at the heterojunction interface between ‐OH and ‐O groups. Consequently, the improved electron delocalization leads to the formation of stronger bonds between Co sites and urea CO(NH2)2, promoting a preference for urea to occupy Co active sites over OH*. The resulting catalyst, Ag−CoOOH@NiOOH, demonstrates ultrahigh UOR activity with a low potential of 1.33 V at 100 mA cm−2. The fabricated catalyst exhibits a mass activity over 11.9 times greater than the initial cobalt oxyhydroxide. The rechargeable urea‐assisted zinc‐air batteries (ZABs) achieve a record‐breaking energy efficiency of 74.56 % at 1 mA cm−2, remarkable durability (1000 hours at a current density of 50 mA cm−2), and quick charge performances. [ABSTRACT FROM AUTHOR]